(a) Differentiate between perceived demand curve and proportional demand curve in a monopolistic competitive market. Explain why…

(a) Perceived vs. Proportional Demand Curve

In Edward Chamberlin’s model of monopolistic competition, the distinction between the perceived demand curve (dd) and the proportional demand curve (DD) arises from individual firm expectations versus collective market realities.

The perceived demand curve (dd) reflects an individual firm’s subjective expectation of sales when it changes its price, assuming all rival firms keep their prices unchanged. Consequently, dd is highly price-elastic because the firm expects to gain or lose substantial market share through cross-brand substitution.

Conversely, the proportional demand curve (DD) traces the actual sales of the firm when all competing firms change their prices simultaneously by the same magnitude. Here, each firm retains its proportional share (1/n) of the total market demand.

The proportional demand curve is steeper than the perceived demand curve because when the entire industry alters prices concurrently, the cross-firm substitution effect is eliminated. A price reduction along DD expands sales solely through total market expansion, whereas a price reduction along dd captures both market expansion and rival customers. Thus, DD possesses lower price elasticity of demand and is strictly steeper than dd.

(b) Classical Dichotomy

The classical dichotomy asserts the strict separation of real variables (relative prices, output, real wages, and employment) from nominal variables (general price level, nominal wages, and money supply). Real variables are determined exclusively in the real sector by factor endowments, technology, and consumer preferences, while nominal variables are determined in the monetary sector via the Quantity Theory of Money (MV = PY). Money is viewed as a mere "veil", exhibiting neutrality in the long run.

Critically, this dichotomy was shown to be logically inconsistent by Don Patinkin. Patinkin demonstrated that classical theory committed an error by assuming the demand for goods depends only on relative prices while simultaneously asserting that the absolute price level is determined by the money market. He resolved this through the "Real Balance Effect": a change in nominal money balances (M/P) alters real wealth, directly impacting the demand for real goods and invalidating the strict dichotomy.

Furthermore, John Maynard Keynes rejected the dichotomy by establishing the monetary transmission mechanism. Money affects the real economy through liquidity preference and the rate of interest, which in turn governs real investment, aggregate output, and employment, confirming that money is non-neutral, particularly in the short run. On balance, the dichotomy is a useful long-run benchmark, since sustained money growth mainly raises prices, but it fails as a description of the short run, where sticky wages and prices let money affect output and employment.

(c) Ad Valorem vs. Specific Sales Tax

From a firm’s perspective, an ad valorem tax (t) is strictly preferable to a specific tax (s) when both generate an identical amount of tax revenue for the government.

Let inverse demand be P(q) with marginal revenue MR(q), and marginal cost be MC(q). Under a specific tax s, the net price received by the firm is P(q) - s, yielding effective marginal revenue MRₛ = MR(q) - s. Under an ad valorem tax rate t, the net price is (1 - t)P(q), yielding effective marginal revenue MRₜ = (1 - t)MR(q) = MR(q) - t · MR(q).

To generate the same tax revenue T at an output q, the rates must satisfy s · q = t · P(q) · q, which implies s = t · P(q).

For any downward-sloping demand curve, price exceeds marginal revenue (P(q) > MR(q)). Substituting s into the marginal revenue equations gives: t · P(q) > t · MR(q) implies s > t · MR(q) implies MRₜ > MRₛ

Now start from the firm's equilibrium under the specific tax, where MR(qₛ) − s = MC(qₛ). Replace s by the ad valorem rate t = s/P(qₛ), which yields exactly the same revenue at qₛ. At qₛ the firm's marginal revenue after tax is (1 − t)MR(qₛ), which is greater than MR(qₛ) − s = MC(qₛ), so the firm gains by expanding output. It therefore ends up with a higher output, a lower price and a higher profit, while the government's revenue tP(q)q does not fall. Under perfect competition (P = MR) the two taxes are equivalent; the advantage exists only when the firm faces a downward-sloping demand curve.

Because the ad valorem tax takes a fixed percentage of price rather than a fixed nominal amount, the tax per unit automatically declines as the firm expands output and lowers price. Consequently, the net demand curve faced by the firm under an ad valorem tax is more price-elastic. The firm experiences lower output restriction, charges a lower consumer price, causes smaller deadweight loss, and retains higher producer surplus and profits compared to an equivalent specific tax.

(d) Treasury Bills and Money Supply Control

Treasury Bills (T-bills)—issued in tenors of 91, 182, and 364 days—are vital instruments of indirect monetary control utilized by the Reserve Bank of India (RBI).

First, the RBI regulates primary liquidity (M₀) through Open Market Operations (OMOs) involving outright sales and purchases of T-bills. Selling T-bills absorbs reserve money from commercial banks, curbing their credit-creation capacity, whereas purchasing T-bills injects high-powered money into the banking system.

Second, under the Liquidity Adjustment Facility (LAF), T-bills serve as primary sovereign collateral for repo and reverse repo operations, allowing the central bank to modulate daily liquidity surpluses or deficits in the interbank market.

Third, T-bills are deployed in sterilization operations. Under the Market Stabilization Scheme (MSS), the RBI issues T-bills to mop up excess domestic liquidity generated from foreign exchange market interventions, preventing inflationary expansion of broad money (M₃).

Finally, T-bill yields establish the risk-free benchmark at the short end of the sovereign yield curve, facilitating effective monetary transmission of the policy repo rate to commercial bank deposit and lending rates.

(e) Assumptions of Neoclassical Loanable Funds Theory

The Neoclassical Loanable Funds Theory of interest, developed by Knut Wicksell and extended by Dennis Robertson, Bertil Ohlin, Gunnar Myrdal and Erik Lindahl, determines the equilibrium rate of interest by the supply and demand for loanable funds. The major assumptions are:

1. Perfect Competition: Financial, factor, and commodity markets operate under perfect competition, ensuring interest rates adjust flexibly to clear the market.
2. Full Employment and Closed Economy: The economy operates at full employment in a closed macroeconomic framework without cross-border capital mobility.
3. Integration of Monetary and Real Factors: The theory synthesizes real factors (productivity of capital and thrift) with monetary factors (bank credit, dishoarding, and cash balances).
4. Supply Composition: Total supply of loanable funds is an increasing function of the rate of interest, consisting of planned savings (S), net additions to bank credit (Δ M), and dishoarding of past balances (DH).
5. Demand Composition: Total demand for loanable funds is a decreasing function of the rate of interest, consisting of gross investment demand (I), intended hoarding (H), and consumption dissaving (DS).
6. Constant Price Level: The general price level is assumed stable during the market-clearing period.
7. Equilibrium Condition: The natural equilibrium rate of interest is attained where total supply equals total demand: S + Δ M + DH = I + H + DS.